Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 tuning machine features an optimized 1:18 gear ratio, engineered to deliver precise, velvet-smooth tuning and dependable pitch stability. Manufactured to exacting CNC tolerances and surface-finished for lasting durability, each unit utilizes a self-locking internal drive mechanism that prevents slippage during performance. High-grade brass string posts fit tightly within the housing to minimize play and ensure long-term, wear-free operation across frequent retuning sessions.
Installation is streamlined via the innovative stepped M6 flanged washer, which aligns the string post through a 0.39 in (10 mm) stepped collar and eliminates the need for tiered headstock reaming. This stepped profile counters tilting moments and distributes lateral mechanical tension away from both the post and the rear mounting screw. Sealed against environmental contaminants, the internal gears are permanently lubricated with proprietary Schaller grease for entirely maintenance-free longevity.
Sharing exact mounting footprint dimensions with classic preceding models, the M6 90 enables direct retrofitting without structural headstock modifications. This hardware suite supports versatile setup configurations, pairing seamlessly with traditional post assemblies or locking options for enhanced string security. Supplied with stepped washers, threaded hollow screws, and mounting hardware, it provides a comprehensive replacement solution for professional musicians and repair technicians.
| Brand | Schaller |
| Model | M6 90 |
| Product Type | Guitar Tuning Machine |
| Gear Ratio | 1:18 |
| Weight per Unit (Small/Large Button) | Metal (1.27 oz / 1.34 oz), Pearloid (1.06 oz / 1.09 oz), Ebony (1.06 oz / 1.09 oz) including hollow screw |
| Button Bore Hole | 0.17 in (4.2 mm) diameter with 0.14 in (3.6 mm) drive surface |
| Product Weight | 0.79 lb |
| Housing Type | Enclosed / Sealed |
| Post Material | Brass |
| Lubrication | Schaller Special Grease (Maintenance-Free) |




















